Mitt Romney says he wouldn’t alter the status of young illegal immigrants already approved for work permits. Some thought the statement was halfhearted, while others said he should have criticized the president.

Mitt Romney finds himself in a familiar position after saying he wouldn’t alter the status of young illegal immigrants granted special protection from deportation by President Obama: He’s not loved by those on either side, and there’s plenty of ambiguity about his stance.

For those in favor of Mr. Obama’s policy, known as Deferred Action for Childhood Arrivals (DACA), Mr. Romney’s statement came off as either halfhearted or only slightly helpful.

For those opposed to the move, he missed an opportunity to criticize what some on the right see as an illegal and perhaps unconstitutional power grab.

DACA is a modified executive-branch version of the more famous DREAM Act legislation, which is currently stalled in Congress. The Obama program allows young illegal immigrants who have been in the United States for at least five years without committing major crimes to receive a two-year “deferred action” from deportation proceedings, as well as the ability to apply for a work permit.

"The people who have received the special visa that the president has put in place, which is a two-year visa, should expect that the visa would continue to be valid. I'm not going to take something that they've purchased," Romney told The Denver Post on Monday. "Before those visas have expired, we will have the full immigration reform plan that I've proposed."

(The DACA program does not, in fact, confer visas on illegal immigrants.)

Crucially, however, Romney didn’t say whether the program would continue under his watch while he pursues a wider-ranging immigration plan. Romney previously promised to veto the DREAM Act.

For some critics, Romney’s lack of distinction on some points is the key stumbling block.

“It tells us all we need to know about Mitt Romney that he sees fundamental fairness and decency for immigrant children who grew up in America as nothing more than a ‘purchase’ he doesn't want to cancel,” said Rep. Luis Gutierrez (D) of Illinois, one of the House’s leading Democratic voices on immigration reform, in a statement. “Protecting these young immigrants from being deported sounds no more important to Mitt Romney than protecting someone who bought a sweater at the mall.”

As a practical matter, however, many potential applicants and immigration advocates have feared what Romney might do with the DACA program. His recent comments, says Morna Ha, the head of a Korean-American group that works on immigration issues, will be incrementally helpful in allaying an applicant’s fears. But they still come up short of what she thinks potential applicants need to hear to encourage them to apply.

“It’s a start to say that he wouldn’t cancel it for the young people who have already applied, but I think it is critical for him to ensure that all of those eligible ... might be able to benefit from this program,” says Ms. Ha, executive director of National Korean American Service & Education Consortium (NAKASEC).

As many as 1.8 million people could be eligible for the program, according to estimates from the Migration Policy Institute, of which 82,000 had applied as of Sept. 13, according to federal data. Of those applicants, more than 1,600 advanced to the final review stage, with a handful of approval decisions rendered, according to the US Citizenship and Immigration Services.

On the other side, conservatives could quibble with the fact that in The Denver Post interview, Romney didn’t take the president to task over how the program was handled (although Romney has done that before). Obama announced DACA as an executive decision to be carried out by the Department of Homeland Security.

“Romney didn’t take the opportunity to say that he’ll stop this power grab in which the president does things that the Constitution assigns to Congress,” says Roy Beck, executive director of NumbersUSA, a group that supports lower immigration levels. “That’s the disappointing part of it, that he didn’t take the opportunity to criticize Obama for having done it this way.”

Mr. Beck also takes issue with the lack of specificity in Romney’s plan to pursue comprehensive immigration reform.

“There’s some kind of a permanent solution, things to do, to help some of these people on a permanent basis that I would assume would have some offsets too,” Beck says, meaning decreasing immigration from other groups in exchange for aid to young illegal immigrants. Romney “just has not laid out any of those things.”